Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. Combustors often operate at high temperatures that may exceed 2,500 degrees Fahrenheit. Typical turbine combustor configurations expose turbine blade assemblies to these high temperatures. As a result, turbine blades must be made of materials capable of withstanding such high temperatures. In addition, turbine blades often contain cooling systems for prolonging the life of the blades and reducing the likelihood of failure as a result of excessive temperatures.
Typically, turbine blades are formed from a root portion at one end and an elongated portion forming a blade that extends outwardly from a platform coupled to the root portion. A turbine blade ordinarily includes a tip opposite to the root section, a leading edge, and a trailing edge. The inner aspects of turbine blades typically contain an intricate maze of cooling channels forming a cooling system. The cooling channels in the blades receive air from the compressor of the turbine engine and pass the air through the blade. The cooling channels often include multiple flow paths that are designed to maintain all aspects of the turbine blade at a relatively uniform temperature.
The trailing edge of a turbine blade is difficult to cool because the trailing edge is often too thin to effectively cool using known embodiments. Because the trailing edge of a blade is difficult to cool and is often exposed to both high temperatures and high loads, the trailing edge may suffer from creep or oxidation during operation. The detrimental effects may be most pronounced in the radially outward portion of the blade proximate to the blade tip because the elongated airfoil is thinner at the tip. The problem is generally most severe in the rear stages of a turbine where the entire elongated airfoil is generally thinner than the elongated airfoils of the front stages. Thus, a need exists for a turbine blade cooling system that effectively cools the trailing edge of a rear stage turbine blade.